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Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with an extremely high lethality rate. Oncogenic KRAS activation has been proven to be a key driver of PDAC initiation and progression. There is increasing evidence that PDAC cells undergo extensive metabolic reprogramming to adapt to their extreme energy and biomass demands. Cell-intrinsic factors, such as KRAS mutations, are able to trigger metabolic rewriting. Here, we update recent advances in KRAS-driven metabolic reprogramming and the associated metabolic therapeutic potential in PDAC.

Objective Basic transcription factor 3 (BTF3) has been shown to exert carcinogenic effects in several types of tumors. But its role in melanoma is still unclear. This study aims to explore the proliferative effect and molecular mechanisms of BTF3 in melanoma. Methods We used GFP-labeled BTF3-shRNA lentiviral vectors to knock down the expression of the BTF3 gene in melanoma cells, and then evaluated the effect of BTF3 on the cell proliferation, cell cycle, apoptosis, and colony formation of melanoma cells through in vivo and in vitro experiments. Furthermore, we selected the representative tumor masses from the xenografted melanoma for microarray hybridization and bio-information analysis to screen out genes that significantly interact with BTF3. Through conducting hierarchical clustering analyze we predicted the prominent pathways and biological effects of BTF3-ralated genes, and further verify the expression of some representative genes by qRT-PCR and western blot. Results BTF3 is heterogeneously expressed in melanoma tissues and cells. Knockdown the expression of BTF3 attenuated the proliferation of melanoma cells both in vitro and in vivo. The melanoma cells exhibited more apoptosis, significant G2/M arrest, and deficient DNA damage repair capability conferred by transfection of BTF3-shRNA lentiviral vector. Furthermore, the results of bioinformatics analysis and western blot assay suggested that BTF3 might involve in p53 signaling, complement system, wnt/β-catenin signaling, FGF signaling, and other classical signaling pathways through interacting with some important genes such as TP53, cyclin dependent kinase inhibitor 1A (CDKN1A), checkpoint kinase 1 (CHEK1), tumor protein p53 inducible protein 3 (TP53I3), and insulin like growth factor binding protein 3 (IGFBP3). The upstream regulators of BTF3 include doxorubicin, nuclear protein 1 (NUPR1), TP53, etc. Conclusion BTF3 promotes the progression of melanoma by interacting with some key genes such as p53. Our findings provide novel insights into the role of BTF3 as an oncogenic gene in melanoma and suggest that BTF3 expression level may serve as a potential biomarker in response to clinical treatment.

Objective: Using brain-dead donors to obtain organs for transplant is an effective way to overcome the shortage of organ donors. The purpose of this study is to investigate ultrasound flow imaging and elastography as a simple, feasible, accurate and effective method for evaluation of liver damage after brain death using an animal model.Methods: We established a brain-death model using 15 pigs. Brain death was induced by progressively increasing the intracranial pressure, and the brain-death state was maintained for 9 hours. Spectral Doppler imaging and elastography was used to evaluate hepatic hemodynamic parameters and tissue stiffness over the period of brain death.Results: Electron microscopy of the liver over the progress of brain death revealed gradual mitochondrial swelling (with rupture), expansion of the endoplasmic reticulum, and increased collagen in the extracellular matrix. Spectral Doppler imagin demonstrated that the HA-RI increased over time, which had statistically significant difference between the Bef-BD measurement and measurements at 3, 6, and 9 hours after brain death. Real time elastography of the liver revealed a gradual decrease of the mean relative strain value (MEAN) over the time, and a gradual increase in standard deviation of the relative strain value, complexity of low strain area, and skewness, suggesting that brain-death induced liver damage increases with time. The ROC curves showed that MEAN had the highest sensitivity, specificity, and accuracy for assessing liver injury.Conclusion: Hepatic tissue damage induced by brain death increased over time. The HA-RI and liver stiffness index changes can be assessed by Doppler ultrasound and elastographic imaging. Our results showed that elastography is a useful method to evaluate liver damage after brain death.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy driven by genetic mutations and/or epigenetic dysregulation. Gemcitabine chemotherapy is the first-line regimen for pancreatic cancer but has limited efficacy. Our previous study revealed the role of SETD2-H3K36me3 loss in the initiation and metastasis of PDAC, but little is known about its role in tumor metabolism. Here, we found that SETD2-deficient PDAC enhanced glycolysis addiction via upregulation of glucose transporter 1 (GLUT1) to meet its large demand for glucose in progression. Moreover, SETD2 deficiency impaired nucleoside synthesis by directly downregulating the transcriptional level of transketolase (TKT) in the pentose phosphate pathway. The metabolic changes confer SETD2-deficient PDAC cells with increased sensitivity to gemcitabine under glycolysis restriction conditions. Collectively, our study provides mechanistic insights into how SETD2 deficiency reprograms glycolytic metabolism to compensate for insufficient nucleoside synthesis, suggesting that glycolysis restriction combined with gemcitabine might be a potential therapeutic strategy for PDAC patients with SETD2 deficiency.

To analyze hepatic hemodynamic parameters detected by Doppler ultrasound (DU) of uncomplicated children with biliary atresia who underwent left lateral segment living donor liver transplantation (LLS-LDLT), explore its normal change trend over time and determine the normal reference interval. We retrospectively involved the data from 227 biliary atresia patients (100 Males,127 Females). Hemodynamic parameters include peak systolic velocity (PSV), end-diastolic velocity (EDV), resistivity index (RI), and pulsation index (PI) of the hepatic artery (HA), portal vein velocity (PVV), portal vein flow (PVF) and hepatic vein velocity (HVV) during intra-operative and on the 1st, 3rd, 5th and 7th day after operation were collected. Repeated measures analysis of the variance and Friedman test were used to analyze the changing trend of hemodynamic parameters over time in the first week after the operation. PSVHA and EDVHA showed a similar changing tendency at one week after surgery, with an overall decrease-rise trend; RIHA and PIHA also changed similarly with an overall rise-decrease trend. The HVV and PVV at surgery were lower than at all time points after surgery. As for PVF, the value of POD5 was the highest and then decreased. Additionally, this study provided the normal reference interval of hemodynamic parameters for LLS-LDLT patients, which were PSVHA: 18.4–98.3 cm/s, EDVHA: 0–43.3 cm/s, RIHA: 0.41–1.0, PIHA: 0.51–2.0, PVV: 19.0–83.7 cm/s, HVV: 19.4–68.0 cm/s, and PVF:99.5–500.0 ml/min/100 g at intraoperation. Within the first postoperative week: PSVHA: 21.0–97.7 cm/s, EDVHA: 0–32.7 cm/s, RIHA: 0.47–1.0, PIHA: 0.62–2.0, PVV: 23.0–92.0 cm/s, HVV: 19.7–86.0 cm/s, and PVF: 100.0–513.0 ml/min/100 g. The hepatic hemodynamic of post-transplanted children detected by DU had specific changing trends and normal ranges, which provides valuable reference values for ultrasonologists and pediatric transplant clinicians.

Perineural invasion is a common feature of pancreatic ductal adenocarcinoma (PDAC). Here, we investigated the effect of perineural invasion on the microenvironment and how this affects PDAC progression. Transcriptome expression profiles of PDAC tissues with different perineural invasion status were compared, and the intratumoral T-cell density and levels of neurotransmitters in these tissues were assessed. Perineural invasion was associated with impaired immune responses characterized by decreased CD8+ T and Th1 cells, and increased Th2 cells. Acetylcholine levels were elevated in severe perineural invasion. Acetylcholine impaired the ability of PDAC cells to recruit CD8+ T cells via HDAC1-mediated suppression of CCL5. Moreover, acetylcholine directly inhibited IFNγ production by CD8+ T cells in a dose-dependent manner and favored Th2 over Th1 differentiation. Furthermore, hyperactivation of cholinergic signaling enhanced tumor growth by suppressing the intratumoral T-cell response in an orthotopic PDAC model. Conversely, blocking perineural invasion with bilateral subdiaphragmatic vagotomy in tumor-bearing mice was associated with an increase in CD8+ T cells, an elevated Th1/Th2 ratio, and improved survival. In conclusion, perineural invasion–triggered cholinergic signaling favors tumor growth by promoting an immune-suppressive microenvironment characterized by impaired CD8+ T-cell infiltration and a reduced Th1/Th2 ratio. Significance: These findings provide a promising therapeutic strategy to modulate the immunosuppressive microenvironment of pancreatic ductal adenocarcinoma with severe perineural invasion.

Smad4, a key mediator of the transforming growth factor-β signaling, is mutated or deleted in 20% of pancreatic ductal adenocarcinoma (PDAC) cancers and significantly affects cancer development. However, the effect of Smad4 loss on the immunogenicity and tumor immune microenvironment of PDAC is still unclear. Here, a surprising function of Smad4 in suppressing mouse PDAC tumor immunogenicity is identified. Although Smad4 deletion in tumor cells enhances proliferation in vitro, the in vivo growth of Smad4-deficient PDAC tumor is significantly inhibited on immunocompetent C57BL/6 (B6) mice, but not on immunodeficient mice or CD8

Genetic and epigenetic alterations play central roles in shaping the immunosuppressive tumor microenvironment (TME) to evade immune surveillance. The previous study shows that SETD2-H3K36me3 loss promotes KRAS-induced pancreatic tumorigenesis. However, little is known about its role in remodeling the TME and immune evasion. Here, it is shown that SETD2 deficiency can reprogram neutrophils to an immunosuppressive phenotype, thereby promoting immune escape during pancreatic tumor progression. By comprehensive profiling of the intratumoral immune cells, neutrophils are identified as the subset with the most significant changes upon Setd2 loss. Setd2-deficient pancreatic tumor cells directly enhance neutrophil recruitment and reprogramming, thereby inhibiting the cytotoxicity of CD8

Owing to the lack of early diagnosis, pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal tumours. Because acinar-to-ductal metaplasia (ADM) is a critical process to pancreatic regeneration and PDAC initiation, we applied GSE65146, a dataset composed of transcripts at different time points in wild-type and Kras

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease with no effective treatment. Cancer cells, especially cancer stem cells (CSCs), redirect immune cells to evade immune surveillance and even coopt these immune cells to support their growth and metastasis. However, the identification of CSCs and how CSCs interact with immune cells in PDAC remain uncharacterized. Here, we report that CD90 is expressed on both stromal and tumor cells and that high expression of CD90 is related to a poor prognosis in patients with PDAC. The CD90 highly expressed (CD90hi) population in PDAC cells harbors high stemness features and tumorigenicity. Notably, CD90 acts as an anchor for monocyte/macrophage adhesion, providing a physical interaction between CD90hi cells and monocytes/macrophages. In response, the crosstalk between CD90hi cells and monocytes/macrophages promotes immunosuppressive features of immune cells, which enhance the stemness and epithelial-mesenchymal transition (EMT) of PDAC cells. Moreover, PD-L1 is dominantly expressed in the CD90hi population, providing another strategy for these cells to evade immune surveillance. These findings provide an understanding of the biological significance of CD90 expression in PDAC cells and uncover a novel mechanism for how "stem-like" PDAC cells evade immune surveillance.

The aim of this study was to investigate the specificity and sensitivity of real-time ultrasound elastography (RTE) in the evaluation of liver damage induced by brain death and the correlation with ultrastructural changes in liver tissue. Eleven RTE parameters before brain death and at 0, 3, 6 and 9 h after brain death in 12 miniature pigs were collected and analyzed, and the correlation of these parameters with electron microscopy results was explored. Six of the RTE parameters, namely, mean relative strain value within the region of interest, standard deviation of the relative strain value within the region of interest, area of low strain within the region of interest, complexity of low strain area within the region of interest, skewness and correlation, significantly differed among the time periods. Categorical data were analyzed using the χ2-test. Spearman's correlation analysis was used for evaluating correlations between RTE parameters and electron microscopy results, and the correlation coefficients (r) were calculated. Electron microscopy results revealed that liver damage gradually increased after brain death, with significant differences between 0 and 9 h (χ2 = 14.143, p value = 0.027). In addition, the six aforementioned RTE parameters significantly correlated with electron microscopy results, with the mean relative strain value within the region of interest being the strongest (r = –0.59, p value

Objectives To investigate the clinical value of non-invasive ultrasound imaging in the evaluation of brain death caused by traumatic brain injury. Methods Thirty-four patients with acute severe traumatic brain injury were admitted to hospital within 48 h after injury. All patients were monitored intracranial pressure, transcranial Doppler, echocardiography examination, collection intracranial pressure, MCA-Vs, MCA-Vd, MCA-Vm, EF, LVMPI, RVMPI and other indicators, and combined with clinical conditions and other related data for comparative study and statistical analysis. Results The blood flow spectrum was characterized by diastolic retrograde blood flow spectrum pattern and nail waveform spectrum shape when the patient had clinical brain death. For the parameters of transcranial Doppler, there were significant differences in MCA-Vm and PI between clinical brain death group and normal control group (P < 0.05). For the parameters of echocardiography, there were statistically significant differences in EF, LVMPI, and RVMPI between clinical brain death group and normal control group (P < 0.05). Conclusion Non-invasive dynamic monitoring of cerebral hemodynamics and cardiac function parameters in patients with severe craniocerebral injury can provide a high accuracy and reliability for the preliminary diagnosis of brain death in patients with severe craniocerebral injury. It is helpful for early evaluation of prognosis and provides effective monitoring methods and guidance for clinical treatment.

Background Impaired or hyperactive pancreas regeneration after injury would cause exocrine insufficiency or recurrent / chronic pancreatitis and potentially carcinogenesis. Macrophages are the most abundant immune cells in the regenerative pancreas, however their phenotype and role remain poorly defined. Method Using caerulein-induced acute pancreatitis (AP) model, we examined the dynamic landscape of pancreatic macrophages throughout the acute inflammation to regeneration phases by flow cytometric and RNA-seq analyses. Liposome depletion of macrophages, Il4ra−/− mice as well as inhibitors were used to elucidate the role and regulatory mechanism of macrophages during pancreatic regeneration. Findings We found that M1 macrophages dominated in the pro-inflammatory phase of AP, while M2-like macrophages dominated during pancreas repair/regeneration. Depletion of macrophages at early or late regenerative stage dramatically blocked the acinar-ductal metaplasia (ADM) or delayed inflammation resolution, respectively. Moreover, alternative activation of macrophages was partially dependent on IL-4RA signaling, and ECM/AKT activation in pancreatic macrophages facilitated inflammation resolution during tissue regeneration. Interpretation Our findings illustrate a dynamic phenotype and function of macrophages during AP repair/regeneration, helping us better understand the mechanism of pancreatic regeneration and providing clues for novel therapeutic strategy., Graphical abstract Schematic diagram of dynamic phenotype and function of macrophages following AP injury, and polarization mechanism of M2 macrophages at ADM stage.Image, graphical abstract

Impaired or hyperactive pancreas regeneration after injury would cause exocrine insufficiency or recurrent/chronic pancreatitis and potentially carcinogenesis. Monocyte/Macrophage is a determinant during the pathogenesis of acute pancreatitis(AP), however little is known about the fate and role of these macrophages during the repair/regeneration phase. Using caerulein-induced AP model, we found M1 macrophages in acute inflammatory phase of AP were switched to M2-like macrophages during the regeneration of the pancreas. Depletion of macrophages at early or late regenerative stage dramatically blocked the ADM or delayed inflammation resolution, respectively. Moreover, M2 activation of macrophages was partially dependent on IL-4RA signaling, and macrophage-derived PI3K/AKT signaling facilitated inflammation resolution during acinar re-differentiation. Together, our findings illustrate a dynamic requirement for macrophages during AP repair / regeneration. Investigating the dynamic phenotype and role of macrophage helps us better understand the mechanism of pancreas regeneration, which would provide clues for novel therapeutic strategy. Funding Statement: This work was supported by Program for professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning No.TP2015007 (J.Xue); Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support No.20161312 (J.Xue); The Shanghai Youth Talent Support Program (J.Xue); Shanghai Rising-Star Program No.19QA1408300 (N.Ning); Natural Science Foundation of China No.81702938, No.81770628 and No. 81970553 (J.Xue), No.81802307(P.Lu). Declaration of Interests: All authors have declared that no conflict of interest exists. Ethics Approval Statement: Animal experiments were approved by the guidelines of the Ren Ji Hospital Institutional Animal Care and Ethics Committee.

The mammalian target of rapamycin (mTOR)/regulatory-associated protein of mTOR (Raptor) pathway transmits and integrates different signals including growth factors, nutrients, and energy metabolism. Nearly all these signals have been found to play roles in skeletal biology. However, the contribution of mTOR/Raptor to osteoblast biology in vivo remains to be elucidated as the conclusions of recent studies are controversial. Here we report that mice with a deficiency of either mTOR or Raptor in preosteoblasts exhibited clavicular hypoplasia and delayed fontanelle fusion, similar to those found in human patients with cleidocranial dysplasia (CCD) haploinsufficient for the transcription factor runt-related transcription factor 2 (Runx2) or those identified in Runx2+/- mice. Mechanistic analysis revealed that the mTOR-Raptor-S6K1 axis regulates Runx2 expression through phosphorylation of estrogen receptor α, which binds to Distal-less homeobox 5 (DLX5) and augments the activity of Runx2 enhancer. Moreover, heterozygous mutation of raptor in osteoblasts aggravates the bone defects observed in Runx2+/- mice, indicating a genetic interaction between Raptor and Runx2. Collectively, these findings reveal that mTOR/Raptor signaling is essential for bone formation in vivo through the regulation of Runx2 expression. These results also suggest that a selective mTOR/Raptor antagonist, which has been developed for treatment of many diseases, may have the side effect of causing bone loss.

Objectives The aim of our study was to evaluate the clinical application of color Doppler flow imaging (CDFI) and acoustic radiation force impulse (ARFI) for the diagnosis of acute rejection after liver transplantation. Methods B-Mode CDFI and ARFI assessments were performed in 76 patients who underwent biopsy after liver transplantation at our institution, between October 2011 and October 2014. The study group included 56 patients with acute rejection confirmed by biopsy, with 20 patients whose liver function recovered within 1 month of transplantation forming the control group. Anteroposterior diameter of the liver, hemodynamic index (consisting of the portal vein diameter, portal vein flow velocity, and hepatic vein flow waveform), and ARFI shear wave velocity (SWV) were measured. We used logistic regression modeling and receiver operating curve to evaluate between-group differences. Results Compared with the control group, patients with acute rejection exhibited increased anteroposterior diameter (P = .035) and change in hemodynamic index (P = .021), including increased portal vein diameter, decreased portal vein flow, and loss of triphasic waveform of hepatic vein flow. Acoustic radiation force impulse SWV was markedly increased in the acute rejection group (P

Small molecule inhibitors for bromodomain and extra-terminal (BET) proteins have recently emerged as potential therapeutic agents in clinical trials for various cancers. However, to date, it is unknown whether these inhibitors have side effects on bone structures. Here, we report that inhibition of BET bromodomain proteins may suppress chondrocyte differentiation and restrain bone growth. We generated a luciferase reporter system using the chondrogenic cell line ATDC5 in which the luciferase gene was driven by the promoter of Col2a1, an elementary collagen of the chondrocyte. The Col2a1-luciferase ATDC5 system was used for rapidly screening both activators and repressors of human collagen Col2a1 gene expression, and we found that BET bromodomain inhibitors reduce the Col2a1-luciferase. Consistent with the luciferase assay, BET inhibitors decrease the expression of Col2a1. Furthermore, we constructed a zebrafish line in which the enhanced green fluorescent protein (EGFP) expression was driven by col2a1 promoter. The transgenic (col2a1-EGFP) zebrafish line demonstrated that BET inhibitors I-BET151 and (+)-JQ1 may affect EGFP expression in zebrafish. Furthermore, we found that I-BET151 and (+)-JQ1 may affect chondrocyte differentiation in vitro and inhibit zebrafish growth in vivo. Mechanistic analysis revealed that BET inhibitors influenced the depletion of RNA polymerase II from the Col2a1 promoter. Collectively, these results suggest that BET bromodomain inhibition may have side effects on skeletal bone structures.

To assess the value of passive leg raising (PLR) combined with echocardiography in predicting volume responsiveness in patients with septic shock.Thirty septic shock patients with spontaneous respiration admitted to intensive care unit (ICU) of Tianjin First Center Hospital from July 2016 to August 2018 were enrolled. PLR and volume expansion (VE) were performed successively. The hemodynamic parameters including left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), stroke volume (SV) and left ventricular ejection fraction (LVEF) before PLR (baseline level), after PLR, immediately after VE were examined by echocardiography, and the central venous pressure (CVP) was monitored. The patients with increase in SV after VE (ΔSV) ≥ 15% were served as reaction group, while ΔSV15% were served as non-reaction group. The changes in LVEDV, LVESV, SV, LVEF and CVP at baseline level, after PLR and after VE were compared between the two groups. Pearson correlation method was used to analyze the correlation between ΔSV, increase in LVEF (ΔLVEF) after PLR and ΔSV, and ΔLVEF after VE. Receiver operating characteristic (ROC) curve was plotted to evaluate the predictive value of ΔSV and ΔLVEF after PLR for volume responsiveness.PLR and VE were successfully performed in 30 patients, of which 23 patients (76.7%) were enrolled in the reaction group, and 7 patients (23.3%) in the non-reaction group. Compared with baseline levels, LVEDV, SV, and LVEF in the reaction group were significantly increased after PLR [LVEDV (mL): 83.5±9.6 vs. 77.1±6.2, SV (mL): 48.5±5.6 vs. 43.2±4.9, LVEF: 0.58±0.04 vs. 0.56±0.06, all P0.05], and CVP was significantly increased after VE [cmHΔSV and ΔLVEF measured by PLR combined with echocardiography can be used to evaluate the volume responsiveness in patients with septic shock and can guide fluid therapy.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with high mortality. Lack of effective treatment makes novel therapeutic discovery an urgent demand in PDAC research. By screening an epigenetic-related compound library, we identified THZ1, a covalent inhibitor of CDK7, as a promising candidate. Multiple long-established and patient-derived PDAC cell lines (PDC) were used to validate the efficacy of THZ1 in vitro. In addition, patient-derived xenograft (PDX) models and animal models of PDAC were utilized for examining THZ1 efficacy in vivo. Furthermore, RNA-Seq analyse was performed to reveal the molecular mechanism of THZ1 treatment. Finally, PDAC cell lines with primary or acquired resistance to THZ1 were investigated to explore the potential mechanism of THZ1 susceptibility. CDK7 inhibition was identified as a selective and potent therapeutic strategy for PDAC progression in multiple preclinical models. Mechanistic analyses revealed that CDK7 inhibition led to a pronounced downregulation of gene transcription, with a preferential repression of mitotic cell cycle and NF-κB signaling-related transcripts. MYC transcriptional was found to be involved in susceptibility of PDAC cells to CDK7 inhibition. In conclusion, Identification of CDK7-dependent transcriptional addiction in PDACs provides a potent therapeutic strategy that targets highly aggressive pancreatic cancer.

During the aging process, bone marrow mesenchymal stem cells (BMSCs) exhibit declined osteogenesis accompanied by excess adipogenesis, which will lead to osteoporosis. Here, we report that the H3 lysine 36 trimethylation (H3K36me3), catalyzed by histone methyltransferase SET-domain-containing 2 (SETD2), regulates lineage commitment of BMSCs. Deletion of Setd2 in mouse bone marrow mesenchymal stem cells (mBMSCs), through conditional Cre expression driven by Prx1 promoter, resulted in bone loss and marrow adiposity. Loss of Setd2 in BMSCs in vitro facilitated differentiation propensity to adipocytes rather than to osteoblasts. Through conjoint analysis of RNA sequencing (RNA-seq) and chromatin immunoprecipitation sequencing (ChIP-seq) data, we identified a SETD2 functional target gene, Lbp, on which H3K36me3 was enriched, and its expression was affected by Setd2 deficiency. Furthermore, overexpression of lipopolysaccharide-binding protein (LBP) could partially rescue the lack of osteogenesis and enhanced adipogenesis resulting from the absence of Setd2 in BMSCs. Further mechanistic studies demonstrated that the trimethylation level of H3K36 could regulate Lbp transcriptional initiation and elongation. These findings suggest that H3K36me3 mediated by SETD2 could regulate the cell fate of mesenchymal stem cells (MSCs) in vitro and in vivo, indicating that the regulation of H3K36me3 level by targeting SETD2 and/or the administration of downstream LBP may represent a potential therapeutic way for new treatment in metabolic bone diseases, such as osteoporosis., Author summary During the aging process, the ability of the mesenchymal stem cells (MSCs) in the bone marrow to generate bone cells declines, and they become more likely to produce fat cells, resulting in brittle, or osteoporotic, bones. Here, we demonstrate that a histone modification—H3 lysine 36 trimethylation (H3K36me3), which is mediated by the enzyme SET-domain-containing 2 (SETD2) and regulates gene expression—plays an essential role in MSC lineage commitment in the bone marrow. We deleted the Setd2 gene in bone marrow mesenchymal stem cells (BMSCs) in mice and found that these mice exhibited reduced bone formation and increased marrow fat accumulation. Notably, we identified Lbp as one of SETD2 functional downstream genes. Overexpression of lipopolysaccharide-binding protein (LBP) could partially rescue the phenotype of SETD2 deficiency in bone marrow stem cells. Further mechanistic studies revealed that H3K36me3 could regulate Lbp transcription by modulating its transcriptional initiation and elongation. Thus, our study provides a new mechanism for MSC fate determination and a therapeutic target for the treatment of osteoporosis.

Multiple regulatory mechanisms control osteoblast differentiation and function to ensure unperturbed skeletal formation and remodeling. In this study we identify histone lysine-specific demethylase 1(LSD1/KDM1A) as a key epigenetic regulator of osteoblast differentiation. Knockdown of LSD1 promoted osteoblast differentiation of human mesenchymal stem cells (hMSCs) in vitro and mice lacking LSD1 in mesenchymal cells displayed increased bone mass secondary to accelerated osteoblast differentiation. Mechanistic in vitro studies revealed that LSD1 epigenetically regulates the expression of WNT7B and BMP2. LSD1 deficiency resulted in increased BMP2 and WNT7B expression in osteoblasts and enhanced bone formation, while downregulation of WNT7B- and BMP2-related signaling using genetic mouse model or small-molecule inhibitors attenuated bone phenotype in vivo. Furthermore, the LSD1 inhibitor tranylcypromine (TCP) could increase bone mass in mice. These data identify LSD1 as a novel regulator of osteoblast activity and suggest LSD1 inhibition as a potential therapeutic target for treatment of osteoporosis., Epigenetics: Taking the brakes off bone formation A molecular brake controlling the differentiation of bone-forming osteoblasts has been identified, which could provide a new therapeutic target for osteoporosis. LSD1 regulates the expression of various genes by interfering with the ability of the cellular machinery to bind to DNA and transcribe it. A previous study had suggested that inhibiting LSD1 in stem cells from human fat promoted the formation of new osteoblasts. To further investigate its role in bone development, Weiguo Zou at the Shanghai Institute of Biochemistry and Cell Biology and colleagues engineered mice which lacked LSD1 in their mesenchymal cells–precursors of bone, muscle and fat cells—the animals had increased numbers of osteoblasts and greater bone mass. Further experiments revealed that blocking LSD1 resulted in increased expression of two osteoblast-stimulating factors, although it may also influence bone resorbing osteoclasts.

The aim of this study was to investigate the value of real-time tissue elastography (RTE) in the evaluation of early graft damage resulting from brain death. We performed RTE before and 0, 3, 6 and 9 h after brain death in a Bama pig model. Eleven RTE parameters were compared among time groups, and their correlations with electron microscopic findings were analyzed. Receiver operating characteristic curve analysis was used to find the RTE parameter cutoff values. The mean relative strain value within the region of interest (MEAN), standard deviation of the relative strain value within the region of interest (SD), percentage area of low strain within the region of interest (%AREA), complexity of low-strain area within the region of interest (COMP), kurtosis (KURT), skewness (SKEW), contrast (CONT) and entropy (ENT) and inverse difference moment (IDM) differed statistically significantly between groups (p

Protein translation regulation has essential roles in inflammatory responses, cancer initiation and the pathogenesis of several neurodegenerative disorders. However, the role of the regulation of protein translation in mammalian skeleton development has been rarely elaborated. Here we report that the lack of the RNA-binding protein sterile alpha motif domain containing protein 4 (SAMD4) resulted in multiple developmental defects in mice, including delayed bone development and decreased osteogenesis. Samd4-deficient mesenchymal progenitors exhibit impaired osteoblast differentiation and function. Mechanism study demonstrates that SAMD4 binds the Mig6 mRNA and inhibits MIG6 protein synthesis. Consistent with this, Samd4-deficient cells have increased MIG6 protein level and knockdown of Mig6 rescues the impaired osteogenesis in Samd4-deficient cells. Furthermore, Samd4-deficient mice also display chondrocyte defects, which is consistent with the regulation of MIG6 protein level by SAMD4. These findings define SAMD4 as a previously unreported key regulator of osteoblastogenesis and bone development, implying that regulation of protein translation is an important mechanism governing skeletogenesis and that control of protein translation could have therapeutic potential in metabolic bone diseases, such as osteoporosis.

The aim of our study was to evaluate the clinical application of color Doppler flow imaging (CDFI) and acoustic radiation force impulse (ARFI) for the diagnosis of acute rejection after liver transplantation.B-Mode CDFI and ARFI assessments were performed in 76 patients who underwent biopsy after liver transplantation at our institution, between October 2011 and October 2014. The study group included 56 patients with acute rejection confirmed by biopsy, with 20 patients whose liver function recovered within 1 month of transplantation forming the control group. Anteroposterior diameter of the liver, hemodynamic index (consisting of the portal vein diameter, portal vein flow velocity, and hepatic vein flow waveform), and ARFI shear wave velocity (SWV) were measured. We used logistic regression modeling and receiver operating curve to evaluate between-group differences.Compared with the control group, patients with acute rejection exhibited increased anteroposterior diameter (P = .035) and change in hemodynamic index (P = .021), including increased portal vein diameter, decreased portal vein flow, and loss of triphasic waveform of hepatic vein flow. Acoustic radiation force impulse SWV was markedly increased in the acute rejection group (P .001). The correlation r-value of measured parameters to acute rejection diagnosis was 0.253 for anterioposterior diameters, 0.271 for change in hemodynamic index, and 0.721 for increased SWV. Shear wave velocity and change in the hemodynamic index had diagnostic value, with an area under the receiver operating curve of 0.933.Combining CDFI with ARFI was useful for the diagnosis of acute rejection after liver transplantation.

Programmed cell death is essential for the development of multicellular organisms, yet pathways of plant programmed cell death and its regulation remain elusive. Here we report that ETERNAL TAPETUM 1, a basic helix-loop-helix transcription factor conserved in land plants, positively regulates programmed cell death in tapetal cells in rice anthers. eat1 exhibits delayed tapetal cell death and aborted pollen formation. ETERNAL TAPETUM 1 directly regulates the expression of OsAP25 and OsAP37, which encode aspartic proteases that induce programmed cell death in both yeast and plants. Expression and genetic analyses revealed that ETERNAL TAPETUM 1 acts downstream of TAPETUM DEGENERATION RETARDATION, another positive regulator of tapetal programmed cell death, and that ETERNAL TAPETUM 1 can also interact with the TAPETUM DEGENERATION RETARDATION protein. This study demonstrates that ETERNAL TAPETUM 1 promotes aspartic proteases triggering plant programmed cell death, and reveals a dynamic regulatory cascade in male reproductive development in rice.